I'll throw in my $.02 here as well:

Our cars may be performance cars but were required to meet emmissions and drivability standard as well so you'll find cam specs coming up a bit short compared to the latest high prformance thing for some American muscle car.

Rating at 1mm lift (or .050), figure the valve shimmed off it's seat this amount then count lift from when it then starts moving more. Why? The part of the cam lobe where it comes on & off the base circle is almost flat; leading to very tiny amounts of lift for the first & last few degrees but can add alot of useless degrees of duration into the cam specs. This is also where the mfg. tolerance cam-to-cam would be found and could lead to several cams coming from the same machine to spec out completely different. " actual" duration is a pretty worthless spec whereas duration at .050 or 1mm is completely usefull.
Try a catalog or website that sells cams and gives both specs; you'll find similar numbers for
a mild performance cam at .050 as the 928 cams.

James, on the question of 1/4 of compression stroke: That would be the indication of a well designed intake; the velocity is still filling the cylinder even after the piston has started to travel upwards. Also around TDC and BDC more of the cranks rotation is being used moving the large rod end side to side as it comes over center, reverses and re-accelerates whereas say, halfway up (down) the stroke most of the rotation is accelerating the piston up or down.

Spec differences on the US cams would most certainly be for emmission purposes.

Of course I could be completely wrong.

 

THAT'S the ticket! Thanks very much.

Never applied the obvious lateral motion of the crank vis a vis the piston at the bottom of the stroke...duh.

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Greg -

You sort of sound like you may have some euro or modified cams that you are in posession of and would like to release? Meaning you have some reco euro cams to sell?

 

That's right Brendon send me a private email if you like, but what I have is this; 80 - 83 euro cams I will have them refinished at standard spec i.e. renitrided or I'm currently investigating a modified grind. The modified grind is similar to the 964 specs and will be achieved by using valve lash caps. The only way to achieve a bigger duration and lift is to take down the base circle and use the lash caps to adjust the loss of that material. We are still investigating the feasability of this, the cost would be about $750 USD.

The standard euro cams renitrided would cost you approx $550 for the pair.(Plus shipping) Also I can supply euro heads and intakes if you require them, all at very reasonable prices, Please let me know.
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OK Wally, this one's for you: Given an early 32-valve (80's) American spec. car, is there much value in a cam swap for street/touring use? to which profile (Porsche or aftermarket)? and does such a swap require any other modifications (like fuel system or ign.)? <img src="confused.gif" border="0">

 

Inadequate data for a meaningful answer.

Or in other words, damifino.

 

I cant wait to see how the "cam-less" motor design is working....all done with magnets/solinoids or something to operate the vavles. Imagine the HP let free! Very intersting!

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